A sure warning sign of self-serving sentimentality is the attempt to aggrandize the dreary present by celebrating the heroic past.

“Kilt,” by Canadian playwright Jonathan Wilson, does exactly that: a figure from the past pops up to tell us that there were heroes then who somehow validate us today.

Tom is an Ontario youth who tells his mother, Esther, he’s in a kilt-dancing class – but he actually dances in a kilt in a gay go-go bar.

Esther is furious when she finds out, but forgets her anger in an effort to get her son to accompany her back to Scotland for her father’s funeral. Tom agrees to go and, in Scotland, meets his feisty aunt as well as a WWII pal of granddad’s, David.

All along, we’ve been getting flashbacks to WWII, where a young kilt-wearing soldier, Mac, befriends a frightened officer, David, and the two men become lovers.

Back at the funeral, the now wise, old David tells Mac’s daughters that he really loved him and Tom that his grandad was a bit of a gay rebel.

Enlivening this implausible and tendentious melodrama, energetically directed by Jack Hofsiss, are a few memorable performances: Tovah Feldshuh makes a bitter and sourly funny Esther, while Kathleen Doyle is a breath of fresh air as Esther’s tipsy and candid sister.

Chris Payne Gilbert plays both grandson and grandfather, but he’s inevitably less effective as the self-pitying dancer than as the tough but tender soldier.